Anastomotic leakage, often followed by serious morbidity or death, is an important complication of resection of the intestine. If surgical technique and judgement are sound, anastomotic leakage seldom occurs. In 205 elective, single layer anastomoses of stomach to duodenum, of small intestine, of colon and of colorectum, clinically apparent leakage did not occur except in 1 of 52 patients after colorectal anastomosis. After resection of the intestine performed as an emergency procedure, anastomotic leakage occurred but was infrequent and could clearly be attributed to poor judgement or technique. Anastomotic leakage need seldom occur if surgical technique and judgment are sound. The efficacy and safety of single layer anastomosis are discussed.